Mary Lee, a pregnant, 3,500-pound maneater, is covering about 40 miles a day this week as she journeys north from Delaware — with her likely destination near Cape Cod.

“She’s probably headed up towards Massachusetts to give birth,” said Marie Levine, executive director of the Shark Research Institute at Princeton.

Since it is unusual for great white sharks to come so close to shore, both New Jersey and New York police don’t have plans in place to alert the public.

But OCEARCH, a nonprofit organization that built an interactive map that tracks tagged sharks like Mary Lee, takes to Twitter every time one of its big friends gets close.

And the public is loving it — with Mary Lee boasting more than 31,000 followers on Twitter.

“I am amused, fascinated & mildly terrified of how close sharks are to us. waves to @MaryLeeShark faints,” tweeted Dina_at_Disney.

Since biologists tagged her back in September 2012, she has traveled more than 15,500 miles — hitting Delaware, Florida, Bermuda and other points along the East Coast, according to OCEARCH’s Facebook page.

She made a similar northern pilgrimage back in 2013 — the last time she was spotted near Long Island.

Chris Berger, the president of OCEARCH, recommended that people marvel at her from afar, saying, “Stay clear of her, stay calm, and appreciate one of the ocean’s greatest living creatures.”

While shark attacks can happen, Levine said they are rare.

“We’re not a normal prey, so I wouldn’t be concerned,” she said, adding that Mary Lee may be going to Raritan Bay for a seal snack.

“Plus, people are swimming with sharks every time they go in the ocean.”